Description: (Applicant's Description) The Flow Cytometry Shared Resource provides the Cancer Center investigators with specialized instrumentation for the quantitative analysis of multiple cellular parameters. The goals of the resource are to provide: instrumentation for flow cytometric analysis and the hardware and software to analyze data obtained from the flow cytometer; consultation and training for scientists in the use and capabilities of the instruments and associated software; and assay implementation for establishing new protocols. The Flow Cytometry Shared Resource has a Becton Dickinson FACScan flow cytometer and a new FAC Station data analysis system with two networked workstations and state-of-the-art software programs. The resource staff consists of a Director and Technical Director who manage Resource policies, fiscal accountability, instrument maintenance, and consultation and training. A Research Associate will be added to complete the staff of the Resource. The Flow Cytometry Resource is a new resource at the Cancer Center that became operational in August 1999. In the first month of operation it was utilized by three NCI-funded research programs for cell cycle analysis, cytotoxicity assays, and quantification of apoptosis.